TW201939878A - Motor device - Google Patents

Abstract

A gear motor (motor device) (1) provided with a three-phase motor (2) and a terminal box (4) which houses a power supply connection terminal (5a) for connecting the three-phase motor (2) to an AC power supply (6) is provided with: a power detection circuit (53) that detects power supplied to the three-phase motor (2); and a control unit (51) that performs prescribed control when an abnormality of a load applied on the three-phase motor (2) or on a device to be driven is detected on the basis of the power detected by the power detection circuit (53). The power detection circuit (53) and the control unit are housed in the terminal box (4).

Description

Motor device

The present invention relates to a motor device that accommodates a power detection circuit in a terminal box of a motor and can accurately detect an abnormality in a load.

A gear motor includes a motor, a reducer that reduces the rotation of the motor and outputs it, and an overload protection circuit. The gear motor is used as a power source of a belt conveyor, for example. The overload protection circuit detects a current flowing in the motor to monitor an overload of the motor or an overload of a driven device such as a belt conveyor driven by a gear motor. When an overload is detected, the overload protection circuit stops the motor and the driven device by blocking the power supply to the motor.

Patent Document 1 discloses a gear motor that performs overload protection by current detection as described above.

Patent Document 2 discloses a power detector that detects a single-phase line voltage and a phase current, calculates a power factor based on a phase difference between the voltage and the current, and obtains three-phase AC power. A transformer is used for detecting the voltage between lines.

Patent Document 3 discloses a motor information terminal device that calculates a load state based on detection signals of a temperature sensor and a vibration sensor provided in a motor.
[Prior Art Literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2011-115025
[Patent Document 2] Japanese Patent Laid-Open No. H5-312854
[Patent Document 3] Japanese Patent Laid-Open No. H5-122985

[Problems to be Solved by the Invention]
Patent Document 1 discloses a configuration in which an electric current is detected to detect an overload. However, if only the electric current is monitored, an abnormality in the load may not be detected. For example, when a gear motor is used as a power source of a belt conveyor, a motor having an output larger than a required power is often selected in consideration of a safety factor. When a high-output motor is used for a belt conveyor, the motor is operated in a region where the load factor is low for the motor, that is, a region where the rated current value is less. At this time, even if the belt conveyor becomes abnormally overloaded, the change in current is small in the characteristics of the motor, and there is a possibility that the overload cannot be detected properly (see FIG. 5). In addition, the current value of the motor also changes due to fluctuations in the power supply voltage, so accurate overload cannot be detected (see FIG. 6).
On the other hand, miniaturization of a gear motor is required, for example, an overload protection circuit is arranged so as not to interfere with a driven device.

An object of the present invention is to provide a motor device that does not depend on the fluctuation of the power supply voltage, and can detect the abnormality of the load of the motor or the driven device with high accuracy even in a light load area, and does not need to be externally arranged and driven. Device interference adds additional circuit devices.
[Means for solving problems]

A motor device according to the present invention includes a motor and a terminal box housing a connection terminal for connecting the motor to an AC power source. The motor device includes a power detection circuit that detects power supplied to the motor, and controls the motor device. The unit executes a predetermined control when an abnormality in the load of the motor or the driven device driven by the torque of the motor is detected based on the power detected by the power detection circuit. A detection circuit and the control unit are housed in the terminal box.

In the present invention, the abnormality of the load in the motor or the driven device is detected by detecting the power supplied to the motor. The abnormality of the load includes not only an overload exceeding a predetermined upper limit value, but also a state of a low load below a predetermined lower limit value. The abnormality of the load is detected by electric power detection, so that it does not depend on the fluctuation of the power supply voltage, and can detect the abnormality of the load of the motor or driven device with high accuracy even in a light load area ( (See Figures 5 and 6).
Furthermore, since the power detection circuit and the control unit are housed in the terminal box, there is no need to externally arrange additional circuit devices that cause interference with the driven device, and the motor device can be made compact.

In the motor device of the present invention, the motor has a star-connected three-phase coil connected to a three-phase AC power connection terminal, and the power detection circuit includes: a star connection to the three-phase AC power connection terminal Three resistors; a voltage detection section that detects the voltage across the resistor corresponding to the phase voltage of one coil; and a current detection section that detects the phase current flowing in the one coil, The control unit calculates electric power to be supplied to the motor based on the voltage across the one resistor and the phase current flowing through the one coil.

In the present invention, the electric power supplied to the motor can be calculated by a small circuit configuration without a transformer. Since there is no transformer, which is a large component, the power detection circuit can be housed in the terminal box reasonably.

The motor device of the present invention includes a blocker that blocks power supply to the motor, and the control unit controls the blocker to an open state when an abnormality of a load is detected.

In the present invention, when the abnormality of the load is detected by the power detection, the blocker can be set to the on state to block the power supply to the motor.

In the motor device according to the present invention, the control unit outputs a content indicating that there is an abnormality in the load when an abnormality in the load is detected.

In the present invention, when an abnormality of the load is detected by the power detection, a signal indicating the abnormality of the load can be output to the outside. That is, the abnormality of the load can be notified to the outside in some form.

The motor device of the present invention includes a vibration detection unit that detects the vibration of the own device, and the control unit detects the own device or the borrower based on the power detected by the power detection circuit and the detection result of the vibration detection unit. An abnormality of a driven device driven by the torque of the motor.

In the present invention, by detecting the power supplied to the motor and the vibration of the motor device, it is possible to detect the abnormality of the load more accurately.

The motor device of the present invention includes a speed reducer that reduces the rotation of the motor and outputs the reduced speed. The vibration detection unit is disposed at the motor, the speed reducer, or a connection portion between the motor and the speed reducer.

In the present invention, an abnormality in the vibration of the motor, the reducer, or a connection portion between the motor and the reducer can be detected to detect an abnormality in the load.

The motor device of the present invention includes: a temperature detection section that detects the temperature of the own device, and the control section detects the own device or the borrower based on the power detected by the power detection circuit and the detection result of the temperature detection section. An abnormality of a driven device driven by the torque of the motor.

In the present invention, by detecting the electric power supplied to the motor and the temperature of the motor device, it is possible to detect the abnormality of the load more accurately.

The motor device of the present invention includes a speed reducer that reduces the rotation of the motor and outputs the reduced speed. The temperature detection unit is disposed at the motor, the speed reducer, or a connection portion between the motor and the speed reducer.

In the present invention, an abnormality in the temperature of a motor, a reducer, or a connection portion between the motor and the reducer can be detected to detect an abnormality in the load.

The motor device of the present invention includes: a vibration detection section that detects vibration of its own device; a temperature detection section that detects the temperature of its own device; and a blocker that blocks power to the motor, and the control section is in When the power detected by the power detection circuit exceeds a predetermined upper power limit threshold or when the power lower limit threshold is insufficient, the vibration detected by the vibration detection unit exceeds a predetermined vibration threshold If the value is detected, or if the temperature detected by the temperature detection unit exceeds a predetermined temperature threshold, the blocker is controlled to be in an on state.

In the present invention, by detecting the power supplied to the motor and the vibration and temperature of the motor device, it is possible to detect the abnormality of the load more accurately, and to block the motor when the abnormality of the load is detected. Power supply.

The motor device of the present invention includes: a threshold setting switch for setting a power upper limit threshold or a power lower threshold threshold for detecting an overload or light load, and the control unit controls the threshold by The power upper limit threshold or the power lower limit threshold set by the limit setting switch is compared with the power detected by the power detection circuit to detect the abnormality of the load.

In the present invention, the threshold power upper limit value or the threshold power lower limit value for detecting the abnormality of the load can be set by a threshold setting switch.

The motor device of the present invention includes: a communication unit that receives a plurality of power upper limit thresholds or power lower limit thresholds set by the threshold setting switch; and a threshold storage unit that receives the A plurality of power upper limit thresholds or power lower limit thresholds are stored in correspondence with the setting values of the threshold setting switch, and the control unit reads from the threshold storage unit and the threshold Comparing the power upper limit threshold or power lower limit threshold corresponding to the set value of the value setting switch with the read power upper limit threshold or power lower limit threshold and the power detected by the power detection circuit, This is used to detect abnormal load.

In the present invention, each set value corresponding to the state of the threshold setting switch may be assigned a power upper limit threshold or a power lower limit threshold to detect an abnormality of the load via the communication section. The user can switch the threshold setting switch to select a desired setting value, thereby simply switching the power upper limit threshold or the power lower limit threshold.

The motor device of the present invention includes a log memory unit that memorizes a plurality of recent power values intermittently detected by the power detection circuit.

In the present invention, the plurality of recent power values intermittently detected by the power detection circuit may be stored as the record information. Recording information can be used to determine the cause of abnormal load.
[Effect of the invention]

According to the present invention, it is possible to detect an abnormality in the load of a motor or a driven device with high accuracy without relying on a change in a power supply voltage, and even in a light load region, and it is not necessary to arrange external interference with the driven device. The additional circuit device can detect the abnormality of the load.

Hereinafter, the present invention will be described in detail based on a diagram showing an embodiment thereof.
FIG. 1 is a side view showing an example of the gear motor 1. The gear motor 1 of this embodiment includes a three-phase motor 2, a reducer 3, a terminal box 4, and an overload protection circuit 5. The gear motor 1 is an example of a motor device of the present invention.

The three-phase motor 2 includes a three-phase coil connected in a star connection, a rotor that rotates by alternating current flowing through the three-phase coil, and a rotating shaft that outputs torque of the rotor.

The speed reducer 3 is connected to the rotation shaft of the three-phase motor 2 and has a gear mechanism and an output shaft that reduce the rotation of the rotation shaft and output the torque of the three-phase motor 2. The gear mechanism is, for example, a known reduction gear mechanism such as a Helical Gear mechanism, a Hypoid gear mechanism, or a worm gear mechanism.

The terminal box 4 is a hollow substantially rectangular parallelepiped housing that houses various terminals related to the driving of the three-phase motor 2, and is provided at an appropriate portion on the side of the casing of the three-phase motor 2. Regarding the terminal box 4, the lateral width of the terminal box 4 as viewed from the centerline direction of the three-phase motor 2 is smaller than the diameter of the casing of the three-phase motor 2 so as not to be connected with the driven device of the gear motor 1. interference. Moreover, it goes without saying that it is desirable that the longitudinal width is also small.

The overload protection circuit 5 of the present embodiment is a circuit that detects an abnormality in the load of the three-phase motor 2 or the driven device by detecting the power supplied to the three-phase motor 2. The overload protection circuit 5 is housed in the terminal box 4.

FIG. 2 is a circuit block diagram illustrating an example of the overload protection circuit 5, and FIGS. 3A and 3B are schematic diagrams illustrating an example of a circuit board of the overload protection circuit 5. The overload protection circuit 5 includes a power connection terminal 5a, a motor connection terminal 5b, a power supply circuit 50, a control section 51, a blocker 52, a power detection circuit 53, a vibration detection section 54, a temperature detection section 55, a recording memory section 56, The limit value storage unit 57, the threshold setting switch 58, and the communication unit 59. In addition, although the recording memory unit 56 and the threshold memory unit 57 are shown separately as functional units, they can also be configured as a single memory.
The overload protection circuit 5 shown in FIG. 3B includes a substantially rectangular first circuit board 5 c and a second circuit board 5 d that are arranged in a double-layer overlap. The first circuit substrate 5c is a lower mother substrate, and the second circuit substrate 5d is an upper daughter substrate. A power connection terminal 5a is disposed on one short side of the first circuit board 5c. The first circuit board 5c is provided with a motor connection terminal 5b, a power supply circuit 50, a breaker 52, a power detection circuit 53, and the like. A threshold value setting switch 58 is arranged on one long side of the second circuit board 5d, and a communication unit 59 is arranged on the other long side. Further, the second circuit board 5d is provided with a control unit 51, a recording memory unit 56, a threshold memory unit 57 and the like.

The power connection terminal 5 a has three terminals for connecting the gear motor 1 to an AC power source 6 that outputs a three-phase AC voltage. The motor connection terminal 5 b has three terminals connected to the three-phase motor 2. The three terminals constituting the motor connection terminal 5b and the three terminals constituting the power connection terminal 5a are individually connected by a power supply line 5e.

The three-phase motor 2 connected to the motor connection terminal 5 b includes a U-phase coil 21, a V-phase coil 22, and a W-phase coil 23 (see FIG. 4) connected in a star connection. The U-phase coil 21, the V-phase coil 22, and the W-phase coil 23 are wound around a stator, for example. When an AC voltage is applied to the U-phase coil 21, the V-phase coil 22, and the W-phase coil 23, a rotating magnetic field is generated. The rotor is rotated by a rotating magnetic field and outputs torque.

A power supply circuit 50 that converts an AC voltage applied to the three-phase motor 2 into a driving voltage for the overload protection circuit 5 is connected to the power connection terminal 5 a and is supplied to each unit. The power supply circuit 50 includes, for example, a transformer that steps down the AC voltage of the AC power source 6, a rectifier circuit that rectifies the AC voltage reduced by the transformer, and a regulator that stabilizes the DC voltage rectified by the rectifier circuit ( regulator).

The control unit 51 is a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a timing unit, and an input / output interface. computer. The control unit 51 controls the operations of the constituent units, and executes processing for detecting an abnormality in the load in the three-phase motor 2 or the driven device by using electric power. When an abnormality is detected, the control unit 51 executes a process of blocking the power supply to the three-phase motor 2 and a process of notifying the outside of the abnormality. All or a part of the control unit 51 may be configured by a dedicated large-scale integration (LSI), a field-programmable gate array (FPGA), or the like.

The interrupter 52 is a switch that interrupts power supply from the AC power source 6 to the three-phase motor 2. The interrupter 52 is, for example, a solid-state relay such as a bidirectional rectifier (triac) provided on the U-phase and W-phase power supply lines 5e. The position where the switch of the blocker 52 is provided is not particularly limited to the U-phase and W-phase. The interrupter 52 is normally closed. When a load abnormality occurs, the opening and closing of the interrupter 52 is controlled by the control of the control unit 51.

The power detection circuit 53 is a circuit that detects one phase voltage and phase current to detect power supplied to the three-phase motor 2.

FIG. 4 is a circuit diagram showing an example of the power detection circuit 53. The left figure in the figure is the equivalent circuit of the AC power supply 6. With the reference voltage to the neutral point N, the power supply that outputs the AC voltage of the first phase (R) of the AC It is represented by a power source and a power source that outputs an AC voltage of the third phase (T).

The right figure in the figure is an equivalent circuit of the three-phase motor 2, which is represented by a U-phase coil 21, a V-phase coil 22, and a W-phase coil 23 having a predetermined resistance value via a star connection. Note that in FIG. 4, the resistance component of each coil is focused on, and is illustrated as a resistor.
Specifically, one end of the U-phase coil 21, the V-phase coil 22, and the W-phase coil 23 is connected to a common neutral point N, the other end of the U-phase coil 21 is connected to a U-phase terminal, and the other end of the V-phase coil 22 It is connected to the V-phase terminal, and the other end of the W-phase coil 23 is connected to the W-phase terminal.

The power detection circuit 53 is a circuit having the same resistance component as the three-phase motor 2. Specifically, the power detection circuit 53 includes a first resistor R1, a second resistor R2, and a third resistor R3 that are star-connected to three terminals of the power connection terminal 5a or the motor connection terminal 5b. One end of the first resistor R1, the second resistor R2, and the third resistor R3 is connected to a common neutral point N, and the other end of the first resistor R1 is connected to the terminal of the first phase (R) and the U-phase. The other end of the second resistor R2 is connected to the terminal of the second phase (S) and the V-phase terminal, and the other end of the third resistor R3 is connected to the terminal of the third phase (T) and the W-phase terminal. The ratio of the resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 is substantially the same as the ratio of the resistance values of the U-phase coil 21, the V-phase coil 22, and the W-phase coil 23. For example, when the resistance values of the U-phase coil 21, the V-phase coil 22, and the W-phase coil 23 are the same, the resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 are also the same resistance. value.

The power detection circuit 53 includes a voltage detection unit 53 b that detects a voltage across the first resistor R1 corresponding to the phase voltage of the U-phase coil 21, and a current detection that detects a phase current flowing in the U-phase coil 21.部 53a. Hereinafter, the voltage across the first resistor R1 is referred to as a phase current. In addition, the power detection circuit 53 calculates a power factor based on the phase difference between the phase voltage and the phase current detected by the voltage detection unit 53b and the current detection unit 53a, and calculates power of one phase. Then, the power detection circuit 53 calculates the power supplied to the three-phase motor 2 by multiplying the power of one phase by 3, and outputs information indicating the calculated power to the control unit 51. The power supplied to the three-phase motor 2 is expressed by the following formula.

P = 3 × Ve × Ie × cosθ ･ ･ ･ （1）

among them,
Ve: effective value of phase voltage
Ie: effective value of phase current
cosθ: power factor θ: phase difference between phase voltage and phase current

The vibration detection unit 54 is, for example, a three-axis acceleration sensor, which detects acceleration in each axial direction, and outputs information indicating the acceleration in each axial direction to the control unit 51. The vibration detection unit 54 is disposed in a casing of the three-phase motor 2.
A configuration including a three-axis acceleration sensor is an example of the vibration detection unit 54, and a known vibration sensor can be used. The installation location of the vibration detection unit 54 is not necessarily limited to the housing of the three-phase motor 2, and may be provided at a connection portion between the three-phase motor 2 and the reducer 3. The vibration detection unit 54 may be provided in the speed reducer 3. It goes without saying that a plurality of vibration detection units 54 may be provided at a plurality of locations of the gear motor 1.

The temperature detection unit 55 includes, for example, a thermistor. The thermistor of the temperature detection unit 55 is arranged, for example, in the case of the three-phase motor 2. The temperature detection unit 55 detects the voltage across the thermistor, converts the detected voltage across the both ends into a temperature, and outputs information indicating the temperature to the control unit 51.
In addition, the configuration including the thermistor is an example of the temperature detection unit 55, and a known temperature sensor can be used, and for example, the temperature can be detected using a temperature measurement resistor, a semiconductor temperature sensor, a thermocouple, or the like. The installation location of the temperature detection unit 55 is not necessarily limited to the housing of the three-phase motor 2, and may be provided at a connection portion between the three-phase motor 2 and the reducer 3. In addition, the temperature detection unit 55 may be provided in the speed reducer 3. It goes without saying that a plurality of temperature detection units 55 may be provided at a plurality of locations of the gear motor 1.

The recording memory unit 56 is a non-volatile memory such as an electrically erasable and programmable read-only memory (EEPROM), a flash memory, and the like, and displays the phase voltage detected by the power detection circuit 53. Phase information, phase current, power, acceleration detected by the vibration detection unit 54, and time-varying information such as temperature detected by the temperature detection unit 55 are stored. The control unit 51 intermittently acquires the information of the phase voltage, the phase current, and the power from the power detection circuit 53 at a sampling interval set by the user, and performs each of the information obtained at the latest predetermined time. memory. For example, the control unit 51 acquires the information of the phase voltage, the phase current, and the electric power at 20 points in time and stores the information in the record storage unit 56. Similarly, the control unit 51 intermittently acquires acceleration and temperature information from the vibration detection unit 54 and the temperature detection unit 55, and memorizes each piece of information obtained at the most recent predetermined time.

The threshold storage unit 57 is a non-volatile memory such as an EEPROM, which is the same as the recording storage unit 56, and stores various thresholds for detecting abnormalities in the load in the three-phase motor 2 or the driven device. For example, memorizing the power upper limit threshold that specifies the upper limit of the load, the lower power limit threshold that specifies the lower limit of the load, the vibration threshold for detecting abnormalities in the load using vibration, and the use of Temperature to detect the abnormality of the load, such as the temperature threshold, the sampling interval of the detected value, and so on. Further, the threshold value storage unit 57 can memorize a plurality of sets of combinations of threshold values.

The threshold setting switch 58 is a switch for appropriately changing a combination of threshold values stored in the threshold storage unit 57. For example, the threshold setting switch 58 is a rotary switch. The user can switch the threshold setting switch 58 to select a setting value "0", a setting value "1", a setting value "2", and a setting value " 3 "and so on. The threshold value storage unit 57 stores a combination of the threshold values in a manner corresponding to each of the set values "0", "1", "2", and "3".

The communication unit 59 includes, for example, a universal serial bus (USB) port for communicating with an external device such as a computer. The control unit 51 transmits and receives information to and from an external device via the communication unit 59. For example, the control unit 51 receives, through the communication unit 59, information indicating combinations of various threshold values and setting values inputted by a computer, and stores the setting values and the threshold values in the threshold value storage unit 57 in correspondence with each other. .
In addition, the control unit 51 transmits the recording information of the detected values such as the power, the phase voltage, the phase current, the vibration, and the temperature stored in the recording memory unit 56 to the external computer via the communication unit 59.
Further, the control unit 51 may be configured to output a signal indicating the abnormality of the load to the outside via the communication unit 59 when an abnormality of the load is detected.

FIG. 5 is a graph showing a relationship between a motor load, a current, and an electric power in a light load region. The horizontal axis represents a motor load, and the vertical axis represents a detected value of electric power or current supplied to the three-phase motor 2. The thick line indicates power, and the dashed line indicates current. In the light load area indicated by the two arrows of "load change", the amount of change in current is small compared to the amount of change in motor load, and it is difficult to detect the abnormality of the load in the area using current detection. On the other hand, in a light-load area, the amount of change in electric power is large relative to the amount of change in the motor load, and the abnormality of the load in the area can be detected by monitoring the power.

FIG. 6 is a graph showing the relationship between the motor load, current, and power when the power supply voltage fluctuates. The horizontal axis represents a motor load, and the vertical axis represents a detected value of electric power or current supplied to the three-phase motor 2. The thick line indicates power, and the dotted line and one-dot chain line indicate current. When the voltage of the AC power source 6 changes as shown in FIG. 6, the current also changes. The dotted line is the current at a voltage of 200 V, and the one-dot chain line is the current at a voltage of 220 V. In such a situation that the power supply voltage changes, the current also changes, so it is impossible to correctly detect the motor load using current detection. On the other hand, regarding the electric power, even if the voltage of the AC power source 6 is changed, it will not be greatly affected, so the motor load can be stably detected.

As described above, the overload protection circuit 5 of this embodiment detects electric power without relying on fluctuations in the power supply voltage, and can accurately detect the three-phase motor 2 or being driven even in a light load region. Abnormal load on the device.
The control unit 51 detects the abnormality of the load by comparing the power detected by the power detection circuit 53 with the power upper limit threshold and the power lower limit threshold. Specifically, when the power detected by the power detection circuit 53 exceeds the power upper limit threshold value, or when the power is lower than the power lower limit threshold value, it is determined that there is an abnormality in the load.
Furthermore, in addition to the abnormality determination of the load using electric power, the control unit 51 may also be used when the vibration detected by the vibration detection unit 54 is equal to or greater than the vibration threshold, or the temperature detected by the temperature detection unit 55 is the temperature. When it is more than the threshold value, it is determined that the load is abnormal. In addition, the control unit 51 may use the detected power, vibration, and temperature to comprehensively determine the abnormality of the load. For example, the control unit 51 may calculate the difference between the power, vibration, and temperature and each threshold value, calculate the average or weighted average of the difference as an index value indicating the abnormality of the load, and compare the index value with a predetermined threshold value. , To determine the abnormal load. When an abnormality of the load is detected, the control unit 51 outputs the open signal to the blocker 52 to block the power supply to the three-phase motor 2. The communication unit 59 outputs a signal indicating an abnormality of the load to the outside.

FIG. 7 is a schematic diagram showing an example of a threshold value setting screen 7, and FIG. 8 is a conceptual diagram showing a record of electric power values during an overload detection. The control unit 51 can send and receive information to and from an external computer via the communication unit 59. For example, the control unit 51 may send structured data that can be displayed on a computer-side browser, and use it to display a setting screen 7 for setting threshold values to accept settings for various threshold values, power sampling intervals, etc. . In addition, the control unit 51 can read the recorded information during the overload detection according to a request from the computer, and send the read recorded information to the computer through the communication unit 59, thereby changing the power when the overload occurs. Graphs, etc. are displayed in the browser.

The setting screen 7 is a browser image. The setting screen 7 includes a threshold input unit 71, a waveform display unit 72, a display switching button 73, and a waveform selection button 74.
The threshold input unit 71 is displayed on the left side of the browser screen, and has an input field (field) “Overpower setting 0” to “Overpower setting 3” for receiving a power upper limit threshold for detecting an overload, Input fields "start time 0" to "start time 3" for receiving the time when the motor is not subjected to overload detection when it is started, and for receiving the duration of the over-threshold value that is judged to be overload. Input fields "shock time 0" to "shock time 3", input field "overheating setting" for receiving temperature threshold, input field "overshock setting" for receiving vibration threshold. The user can set various threshold values for the overload protection circuit 5 by inputting various threshold values of the respective input fields. The values of "0" to "3" correspond to the setting values of the threshold setting switch 58 as a rotary switch. In addition, in FIG. 7, only the power upper limit threshold value is accepted, but the power lower limit value may be accepted in the same manner.

The waveform display unit 72 is a display unit that displays a record of a power value before an overload is detected by a waveform. Specifically, as shown in FIG. 8, a horizontal axis indicating time, a vertical axis indicating power value, a dotted line indicating a threshold value for determining whether or not the power is excessive, and a waveform of the power value are displayed. The circle displayed on the waveform indicates the power value detected at the sampling time.
The waveform display unit 72 may also display waveforms of phase voltage, phase current, temperature, and vibration acceleration during overload detection.

Further, on the right side of the setting screen 7, display of a detection value waveform for real-time detection of the power waveform displayed on the waveform display section 72 and a detection value waveform before a time point of occurrence of an overload that is memorized as a record is displayed. Switch button 73. When the display switching button 73 is operated, the control unit 51 sends any one of the detection value detected in real time or the information recorded in the detection value stored in the storage unit 56 to the computer via the communication unit 59 in accordance with the operation.
Further, on the right side of the setting screen 7, a waveform selection button 74 for selecting content displayed as a waveform displayed on the waveform display section 72 is displayed, for example, a "voltage" button, a "current" button, a "power" button, and a "temperature""Button," acceleration X axis "button," acceleration Y axis "button," acceleration Z axis "button. The control unit 51 sends the recorded information of the voltage, current, power, temperature, and acceleration stored in the recording memory unit 56 to the computer via the communication unit 59 according to the selected button.

According to the gear motor 1 configured as described above, it is possible to detect abnormalities in the load of the three-phase motor 2 or the driven device with high accuracy even in a light load region without depending on the fluctuation of the power supply voltage.
In addition, since the power detection circuit 53 and the control unit 51 are housed in the terminal box 4, it is not necessary to externally arrange additional circuit devices that cause interference with the driven device, and the gear motor 1 can be made compact.

Furthermore, the power supplied to the three-phase motor 2 can be calculated by a small circuit configuration without a transformer as a large component. Therefore, the power detection circuit 53 can be properly housed in the terminal box 4.

Furthermore, when an abnormality of the load is detected by the power detection, the interrupter 52 may be set to the on state to block the power supply to the three-phase motor 2.

Furthermore, when an abnormality of the load is detected by the power detection, a signal indicating the abnormality of the load can be output to the outside.

Furthermore, by detecting the electric power supplied to the three-phase motor 2 and the vibration and temperature of the gear motor 1, it is possible to detect the abnormality of the load more accurately. Disconnect power to the three-phase motor 2.
In particular, abnormalities in vibration and temperature in the three-phase motor 2, the reducer 3, or the connection portion between the three-phase motor 2 and the reducer 3 can be detected to detect an abnormal load.

Furthermore, a threshold value for detecting an abnormality of the load can be set by the threshold value setting switch 58.

Furthermore, the user can assign a threshold value for detecting an abnormality of the load to each setting value corresponding to the state of the threshold value setting switch 58 via the communication section 59, and can switch the threshold value setting switch 58 To select the desired setting, simply switch the threshold.

Furthermore, the most recent record information of a plurality of voltages, currents, power, vibrations, and temperatures that are intermittently detected by the power detection circuit 53 is stored in the record storage unit 56 so that the user can confirm when an abnormality in the load occurs. Previous power, vibration, temperature, etc. In particular, the recorded information of electric power is important information for determining the cause of abnormal load.

The embodiments disclosed this time should be considered in all respects as illustrative and not restrictive. The scope of the present invention is expressed by the scope of the patent application rather than the meanings described, and is intended to include all modifications and meanings within the scope and scope of the patent application.

1‧‧‧ Gear Motor

2‧‧‧ three-phase motor

3‧‧‧ reducer

4‧‧‧Terminal Box

5‧‧‧ Overload protection circuit

5a‧‧‧Power connection terminal

5b‧‧‧Motor connection terminal

5c‧‧‧1st circuit board

5d‧‧‧ 2nd circuit board

5e‧‧‧power line

6‧‧‧AC Power

21‧‧‧U-phase coil

22‧‧‧V phase coil

23‧‧‧W phase coil

50‧‧‧Power circuit

51‧‧‧Control Department

52‧‧‧Blocker

53‧‧‧Power detection circuit

53a‧‧‧Current detection department

53b‧‧‧Voltage detection department

54‧‧‧Vibration detection department

55‧‧‧Temperature detection department

56‧‧‧Record Memory

57‧‧‧Threshold Memory

58‧‧‧Threshold setting switch

59‧‧‧Ministry of Communications

7‧‧‧ setting screen

71‧‧‧Threshold input unit

72‧‧‧ Waveform display section

73‧‧‧Display cutover button

74‧‧‧ Waveform selection button

R1‧‧‧The first resistor

R2‧‧‧Second resistor

R3‧‧‧3rd resistor

N‧‧‧ neutral point

R‧‧‧Phase 1

S‧‧‧Phase 2

T‧‧‧Phase 3

U‧‧‧U Phase

V‧‧‧V phase

W‧‧‧W phase

FIG. 1 is a side view showing an example of a gear motor.

FIG. 2 is a circuit block diagram showing an example of an overload protection circuit.

3A is a schematic diagram showing an example of a circuit board of an overload protection circuit.

3B is a schematic diagram showing an example of a circuit board of an overload protection circuit.

FIG. 4 is a circuit diagram showing an example of a power detection circuit.

FIG. 5 is a graph showing the relationship between the motor load and the current and power in the overload region.

FIG. 6 is a graph showing the relationship between the motor load, current, and power when the power supply voltage fluctuates.

FIG. 7 is a schematic diagram showing an example of a threshold setting screen.

FIG. 8 is a conceptual diagram showing the recording of electric power values during overload detection.

Claims (12)

A motor device includes a motor and a terminal box housing a connection terminal for connecting the motor to an AC power source. The motor device includes: A power detection circuit that detects power supplied to the motor; and The control unit executes predetermined control when an abnormality in the load of the motor or the driven device driven by the torque of the motor is detected based on the power detected by the power detection circuit, The power detection circuit and the control unit are housed in the terminal box. The motor device according to item 1 of the scope of patent application, wherein: The motor has a star-connected three-phase coil connected to a three-phase AC power connection terminal, The power detection circuit includes: Three resistors star-connected to the three-phase AC power connection terminal; A voltage detecting section that detects a voltage across the two resistors corresponding to a phase voltage of one coil; and The current detection unit detects a phase current flowing in the one coil, 所述 控制 部 The control section The electric power supplied to the motor is calculated based on the voltage across the one resistor and the phase current flowing in the one coil. The motor device according to item 1 or item 2 of the patent application scope, which includes: A blocker that blocks power to the motor, 所述 控制 部 The control section When an abnormality of the load is detected, the blocker is controlled to an open state. The motor device according to any one of claims 1 to 3, wherein the control unit When an abnormality in the load is detected, a content indicating that the load is abnormal is output. The motor device according to any one of claims 1 to 4, including: The vibration detection unit detects the vibration of the own device, 所述 控制 部 The control section Based on the power detected by the power detection circuit and the detection result of the vibration detection unit, an abnormality of the own device or the driven device driven by the torque of the motor is detected. The motor device according to item 5 of the patent application scope, comprising: A reducer that reduces the rotation of the motor and outputs it, The vibration detection unit It is arranged at the motor, the speed reducer, or a connection portion between the motor and the speed reducer. The motor device according to any one of claims 1 to 5, which includes: The temperature detection unit detects the temperature of the own device, 所述 控制 部 The control section Based on the power detected by the power detection circuit and the detection result of the temperature detection unit, an abnormality of the own device or the driven device driven by the torque of the motor is detected. The motor device according to item 7 of the patent application scope, comprising: A reducer that reduces the rotation of the motor and outputs it, The temperature detection section It is arranged at the motor, the speed reducer, or a connection portion between the motor and the speed reducer. The motor device according to item 1 or item 2 of the patent application scope, which includes: The vibration detection unit detects the vibration of the own device; A temperature detection unit that detects the temperature of its own device; and A blocker that blocks power to the motor, 所述 控制 部 The control section When the power detected by the power detection circuit exceeds a predetermined power upper limit threshold or when the power lower limit threshold is insufficient, the vibration detected by the vibration detection unit exceeds a predetermined vibration threshold. In the case of a limit value, or when the temperature detected by the temperature detection unit exceeds a predetermined temperature threshold value, the blocker is controlled to be in an on state. The motor device according to any one of claims 1 to 9 of the scope of patent application, comprising: Threshold setting switch, used to set the power upper limit threshold or power lower limit threshold for detecting overload or light load. 所述 控制 部 The control section The abnormality of the load is detected by comparing the power upper limit threshold or the power lower limit threshold set by the threshold setting switch with the power detected by the power detection circuit. The motor device according to item 10 of the patent application scope, comprising: The communication unit receiving a plurality of power upper limit thresholds or power lower limit thresholds set by the threshold setting switch; and The threshold storage unit is configured to memorize a plurality of power upper thresholds or power lower thresholds received by the communication unit in correspondence with the set values of the threshold setting switch, 所述 控制 部 The control section Reading the power upper limit threshold or power lower limit threshold corresponding to the set value of the threshold limit setting switch from the threshold storage unit, and reading the read power upper limit threshold or power lower limit threshold The value is compared with the power detected by the power detection circuit, thereby detecting the abnormality of the load. The motor device according to any one of claims 1 to 11 of the scope of patent application, comprising: The recording and memory unit memorizes a plurality of recent power values intermittently detected by the power detection circuit.